A number of different compositions and methods that provide hypobromous or hypochlorous acid for disinfecting water systems have been utilized. These technologies currently in use have some serious deficiencies. Trichloro-s-triazinetrione (T.C.C.A.) can be pressed into a solid composition such as a stick, tablet or puck and placed in an erosion feeder, skimmer, or a floating slow release device. However, for a number of applications these solid compositions erode too rapidly. In some cases they do not maintain their integrity as water is circulated through the release device. Consequently, the disinfectant splits, cracks and breaks into small pieces. These small pieces expose more surface area and increased erosion occurs. The disinfectant is released too rapidly and is not satisfactory for the treatment of most water systems. This is also true of blended compositions containing T.C.C.A. and sodium bromide. An example blend contains 96% T.C.C.A., 2% sodium bromide and 2% inert. In other cases as the water temperature increases the erosion rate of the disinfectant increases. The disinfectant is then released too rapidly into the water system and is not satisfactory for treatment of most water systems.